// PHP_VERSION_ID is defined as a number, where the higher the number // is, the newer a PHP version is used. It's defined as used in the above // expression://// $version_id = $major_version * 10000 + $minor_version * 100 + $release_version;//// Now with PHP_VERSION_ID we can check for features this PHP version // may have, this doesn't require to use version_compare() everytime // you check if the current PHP version may not support a feature.//// For example, we may here define the PHP_VERSION_* constants thats // not available in versions prior to 5.2.7

User Contributed Notes 4 notes

If you're trying to check whether the version of PHP you're running on is sufficient, don't screw around with `strcasecmp` etc. PHP already has a `version_compare` function, and it's specifically made to compare PHP-style version strings.